Demountable stair structure



Aug. 29, 1950 L. J. BRUNE, SR

DEMOUNTABLE STAIR STRUCTURE 2 Sheets-Sheet 1 Filed Aug. 9, 1944,

F IG 1.

FIG. 2.

INVENTOR.

LOUIS J. BRUNE,SR. wxfl A ORNEYS.

Aug. 29, 1950 BRUNE, 5 2,520,452

DEMOUNTABLE STAIR STRUCTURE Filed Aug. 9, 1944 2 Sheets-Sheet 2 FIG-.5.

lNVENTOR.

LOUIS J. BRUNE,SR.

/ ATTORNEYS.

Patented Aug. 29, 1950 STATES 2,520,452 nEMouNTABLE STATE swans-runs-Louis J. Brune, Sin, OceahSQr-ingall/I-iss,

Application August. .9, 194 $erialNo,

Tins; invention relates to improvements in; stair ggnstructions. The;primary object ofthis invention is the prcvisien ofa preferably concreteor plastic demountable stair structure-which may beassemor-d-isassembledby an unskilled person. It relatively simple (havingfew parts) anddurable and maybe economically fabricated.

ig fur therobject of this invention is the provision-of a stairconstruction including a pluralityof= stringer and step units which areinterconnected in such an efficientmanner as to provid a steady anddurable stair structure which 9199s not require a concrete base orfoundation. @therobjects and advantages of" the invention Wllllbfiapparent from the following detailed descript-ion.

In the accompanying drawings, forming a part of this specification, andwherein similar reference characters designate corresponding partsthruout the several views- Figure l is a side elevation of the stairstructure showing the Various assembled details thereof.

Figure 2 is a rear view of the assembled stair structure.

Figure 3 is a cross sectional view taken thru a portion of the stairstructure substantially on the line 3--3 of Figure 2.

Figure 4 is a fragmentary cross sectional view thru the lower portion ofone of the stringers of the stair structure.

Figure 5 is a fragmentary cross sectional view taken thru one of theinner connecting parts of adjacent step units.

Figure 6 is a perspective view of the intermediate step unit.

In the drawings, wherein for the purpose of illustration is shown only apreferred embodiment of the invention, the letter A may generallydesignate the improved stair structure. It may include stringer or sidewall units B and C supporting the lower and upper step units D and Frespectively and intermediate step unit E.

It is understood that the invention is not to be restricted to anyparticular number of step units. However, in usual practice the sidewall members will be of the same construction, and all intermediate stepunits will be of the same structure. The top and bottom step units willdiffer slightly, as shown.

It is preferred to construct the various units of the stair structure ofconcrete. The concrete may be reinforced if desired. Plastic material.of any kind may also be used.

1. Claim. (01. lg-e26?) The side-wallste supports or-stringers Band 0'each include abody portion It nawmamseg and outer base flanges ltl andl2- alengthe lower margin thereof. The stringer is stepped as stringersusually areto support the units D; E and F, including the vertical sidesor engaging edges l Sand the horizontaltread-supporting sur faces H. Thelatter surfacesl l areprovided with downwardly convergent taperedsockets 18 intermediate the ends of-- each of these surfaces ll.Preferably one socket in eachhorizontial surface I! will suflice;altho-moresockets may beusedif desired; The top surface H of thestringers B and Cterminates short of therear edge is of the body H11 andat this cornerthereis provided-a cut-out socket;

The lower step unit D- includes a vertical rises 25 and a horizontaltread 2G integral therewith. These portions 25 and 26 are of the desiredthickness. The riser 25 is plain, altho if desired it may be providedwith base flanges. The tread 26 on the under surface thereof at eachside is provided with a depending frusto-pyramidal or tapered lug 30adapted to seat in the lowermost stringer socket I8, as shown in Figure1 of the drawings. The tread 26 is furthermore provided along the rearmarginal portion thereof with downwardly convergent tapered sockets orperforations 3|, shown in Figures 5 and 6 of the drawings, which arepreferably extended the entire way thru the thickness of the tread tofacilitate drainage, should such be needed.

The intermediate step units E are formed somewhat similar to the stepunit D, each including a riser portion 25 and a tread portion 26*. Thelatter are provided with sockets 3| similar to the sockets 3| abovedescribed, and also retaining lugs 30 0n the under surfaces: for thestringers B and C. The feature distinguishing the intermediate stepunits from the lower step unit D is the provision of retaining lugs 40on the lower edge of the riser 25* which are of frusto-pyramidalconstruction, the same as the lugs 3|] above described, adapted to seatin the sockets 3| or 3P as the case may be, of the tread of the nextlower step unit.

The upper step unit F includes a riser 25 and a tread 26'. The former isprovided with the lower marginal frusto-pyramidal lugs 40 adapted forseating in the sockets of the next lower step unit tread, and the tread26 is provided with the frusto-pyramidal shaped stringer receiving lugs30 adapted to seat in the sockets on the top edge l'l of the side wallsor stringers B and C, as shown in Figure 3. The distinguishing featureof the top ste unit F over the other step units is that the tread 26*along the rear margin thereof, is provided with a depending retainingskirt or flange, the entire width thereof, adapted to seat in thecut-out notches or sockets 20 at the upper rear corners of the stringersB and C. It is apparent from the foregoing description that thestringers B and C, with the step units assembled as shown, will providea sturdy and durable stair structure which obviously can be assembled ordisassembled by an inexperienced person. The device includes but a fewnumber of parts compared to demountable stair structures of the priorart and it does not require a stabilizing foundation structure, sinceall of the parts are firmly interlocked. Plastic or cement may be usedin the sockets to additionally anchor the lugs if desired, altho such isnot necessary.

Various changes in the shape, size and arrangement of parts may be madeto the form of the invention herein shown and described, withoutdeparting from the spirit of the invention the scope of the followingclaim. I

I claim: I v A demountable stair structure comprising stringers havingstepped tread mounting edges provided with laterally closed.convergently tapered sockets therein, individual step units eachincluding integral riser and tread portions, the under surfaces of thetread portions having depending inverted pyramidal-shaped lugsinterfitting in the sockets of the stringers, the riser portions at theloweredges thereof having inverted pyramidal-shaped retaining lugsthereon spaced from the stringers, and the tread portions of the stepunits below the uppermost step unit having along the rear marginsthereof convergently tapered perforations extending through the treadportions from their upper surfaces to their under surfaces and receivingthe depending lugs on the lower edges of the riser portions of 5adjacent step units, whereby said perforations also provide drains, thestringers at the upper corners thereof being notched and the uppermoststep unit having a skirt depending from the rear margin of the treadportion along the length thereof and fitting in said notches.

LOUIS J. BRUNE, SR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 530,119 Niederlaender Dec. 4,1894 534,462 Balsley Feb. 19, 1895 952,918 Mann Mar. 22, 1910 1,265,949Osborn May 14, 1918 1,533,166 Daly Apr. 14, 1925 1,745,087 Floto Jan.28, 1930 1,756,351 Gentile Apr. 29, 1930 1,954,722 Bateson et al. Apr.10, 1934 1,964,660 Buzby June 26,1934 2,221,358 Neal Nov. 12, 19402,239,428 Michaud et al Apr. 22, 1941 2,262,127 Wolf Nov. 11, 19412,330,148 Rogge Sept. 21, 1943 FOREIGN PATENTS Number Country Date49,538 Switzerland 1910 527,328 France of 1921 613,612 France of 1926.

